The present invention pertains to a cylinder head gasket according to the preamble of Claim 1.
In principle, two combustion chamber gasket concepts are possible for cylinder head gaskets that are built out of several layers of steel. For both, it is common for the sealing of the combustion chamber passage to be accomplished by a combustion chamber bead running essentially along the edge of the combustion chamber passage. By pressing the cylinder head against the cylinder head gasket and the underlying cylinder block, the combustion chamber bead can be compressed, thereby guaranteeing its sealing function. It is possible for the combustion chamber bead deformed under this pressure to provide a combustion chamber bead support, a so-called stopper. This construction guarantees that when power is shunted, the combustion chamber bead is compressed and the combustion chamber bead cannot become flattened, as with variants without a stopper.
DE 195 15 329 C1 discloses a cylinder head gasket, which in one embodiment features a sealing plate that features several combustion chamber passages arranged adjacent to each other. Around each combustion chamber passage there is a combustion chamber bead, wherein on the side of the combustion chamber bead facing away from the combustion chamber passage there is a stopper that is adjacent to the side of the combustion chamber bead. The individual combustion chamber passages are separated by only a very small distance, so that the stopper is interrupted in the connecting region between two adjacent combustion chamber passages. The stopper only extends a small amount in the lateral direction, so that for a two-cylinder series motor, the stopper has the form of xe2x80x9ceyeglasses.xe2x80x9d
The device according to the prior art has the disadvantage that the device is only supported in the region directly around the combustion chamber bead, while other beads, for instance, a half-bead located at the edge, can become flattened. If beads are supported on one side in a single cylinder head gasket other beads, which, however, are also dependent on support, are not thusly supported, so that the cylinder head gasket loses its elastic deformability, which can lead to reduced seeing characteristics or to deformation of adjacent components.
The objective of the present invention is to overcome the disadvantages of the state of the art mentioned above.
This objective is realized by the cylinder head gasket according to Claim 1. Here, because the stopper essentially extends across the entire surface of the sealing plate where there are no openings, beads that are not combustion chamber beads are also supported by the stopper which protects the combustion chamber bead. Thus, combustion chamber beads, beads around the passages, as well as edge beads can be protected by a single stopper. In this way, the expense of construction or assembly of the cylinder head gasket can be considerably reduced.
Advantageous refinements of the present invention are given in the subordinate claims.
The configuration of the stopper can be chosen arbitrarily. Thus, for instance, it is also possible to provide a stopper that is integrated into the sealing plate. Here, the stopper is formed from an increase in thickness of the sealing plate. However, it is also possible to provide separate stopper elements. An especially cost-effective variant configures the stopper with an essentially constant thickness at the side of the stopper plate adjacent to the combustion chamber bead.
In another advantageous embodiment, the cylinder block features cylinder liners. Cylinder blocks in modern combustion engines are often built from several parts, wherein cast iron cylinder liners are molded or inserted into an aluminum base block. These multiple parts can lead to displacements of the cylinder liners in the aluminum base block. Thus, one goal is to achieve an optimum sealing effect in the region between the cylinder head and the cylinder block on the one hand, while preventing the vertical pressure from building up too high on the cylinder liner on the other. It is possible to arrange the deformable combustion chamber bead directly at the edge of the combustion chamber passage and to arrange the stopper on the side of the combustion chamber bead facing away from the combustion chamber passage, so that for maximum possible joining pressures of the cylinder head gasket, the deformation by the section of the stopper between the cylinder base block and the cylinder head is limited and does not load only the cylinder liner.
Additional advantageous embodiments are given in the subordinate claims.